Polycord welding

[Spen.M.P.]

The past several years I have used both a jig and without a jig. The jig I used was a simple piece of wood with two clamping latches on it that held the to ends tight. Then I melted the ends with a lighter or soldering iron and pushed them together. After that year, I have just held them together with two pairs of pliers then heated up the ends and pushed together. Note: second method requires two people.

[akoscielski3]

Is welding better than using the inserts?

Our team chose to use the inserts because it would be faster to fasten them together and my teacher thinks that welding it is crazy. And it seems easy to repair if broken or easy to replace if we ever need to becuase you can connect the polycord while on the robot. If i am wrong with anything please explain...
Thanks

[JamesCH95]

My text-book understand of polycord is that the inserts require a large pulley radius to work properly, something on the order of 4"-5", which is annoyingly big.

[MrForbes]

The McMaster Carr catalog pages for the cord show hollow cord, with the minimum pulley size, and based on that we bought the hollow 1/4" cord and the aluminum connectors to use on 2 inch OD "pulleys". So far it works fine. If we do have problems with the connectors, we could weld it together.

[Chris Hibner]

Originally Posted by akoscielski3

Is welding better than using the inserts?

Our team chose to use the inserts because it would be faster to fasten them together and my teacher thinks that welding it is crazy. And it seems easy to repair if broken or easy to replace if we ever need to becuase you can connect the polycord while on the robot. If i am wrong with anything please explain...
Thanks

We've had polycord break during a match (got snagged and broke). Fixing it with welding while on the robot is easy - 1) grab each end of the broken cord, 2) heat ends until gooey, 3) press together until hard (about a minute).

If a blob forms when pressing together, it can be easily trimmed to remove the blob with an x-acto knife.

(edit: BTW, I don't recall ever seeing polycord snap at a weld. I'm sure it has happened, but the weld seems just as strong as the rest of the cord.)

[Aren_Hill]

Originally Posted by DonRotolo

4: Use a thin flat plate or blade that is hot (like a soldering iron tip) to put between the cut ends, then just pull it away when you have good melting. Heat gun won't work.
5. Once it reaches room temperature it is as strong as it will ever be. Don't need to wait hours. After pressing together, cool it with a little water, no need to wait minutes.

I have had success using a heat gun to weld polycord, I basically choose my method depending on what i can find that gets hot, usually don't have an alignment jig, just by hand.